383 



extend further back than the premaxillaries. The premaxillaries contract towards that 

 extremity, which is obliquely truncate, and strongly contrast with the expanded extremities 

 of the same bones in the Asiatic Porcupine. The antero-inferior root of the zygoma is 

 stronger in proportion. The facial part of the lacrymal is as small as in the Asiatic species. 

 The hinder border of the lower jaw is slightly concave. The last molars, m 3, are in place, 

 and worn ; the premolars have risen into place in the lower jaw, but their summits are 

 unworn : the deciduous molars are still retained in the upper jaw. The cavity of reserve of 

 the germ of the upper premolar is exposed on the right side. The basisphenoid and pre- 

 sphenoid have coalesced with each other and with their respective alee. The alisphenoid 

 canal, in which a portion of quill is passed on the right side, commences at the middle of the 

 inner surface of the alisphenoid, and perforates it obliquely forwards. The ectocarotid canal, 

 through which a bristle is passed, commences at the posterior border of the alisphenoid, and 

 emerges near the anterior border of its ectopterygoid plate : this, as in other Porcupines, 

 articulates suturally with the pterygoid proper, forming with that and with the broad ento- 

 pterygoid plate a large oblong interpterygoid canal. A bristle is passed through the small 

 entocarotid canal on the right side. 



Presented by Sir Stamford Raffles, P.Z.S. 



2112. The cranium of a young Java Porcupine (Hystrix Javanicd). 



Some of the bones, e. g. the basioccipital and exoccipitals, have been detached. The 

 suture between the superoccipital and the large interparietal is obliterated on the outside, but 

 not on the inside of the skull. The inferior and external angle of the superoccipital fits into 

 a notch of the mastoid, and articulates anteriorly with the end of the squamosal : the mas- 

 toid, petrosal, and tympanic have coalesced into a single bone. There is a deep, but narrow, 

 cerebellar fossa in the petrosal above the ' meatus internus,' and a convex swelling at its fore 

 part, formed by a tympanic air-cell, which communicates by a contracted aperture with that 

 chamber of the tympanum which lodges the membrana tympani. The squamosal overlaps 

 the lower border of the parietal, from which it is partially separated by the sinus opening 

 above the tympanum. The molars in use are |^|, the first being the deciduous molar, the 

 second the first true molar. The summit of the second true molar may be discerned in its 

 almost closed alveolus. 



Presented by Sir Stamford Raffles, P.Z.S. 



2113. The skeleton of a young crestless Porcupine {Hystrix aJopkus). 



The vertebral formula is : 7 cervical, 14 dorsal, 5 lumbar, 3 sacral, and 15 caudal. The 

 accessory tubercle begins to be developed above the diapophysis of the fourth dorsal, expands 

 upon the eighth, and divides upon the ninth : this and the three following vertebras show 

 very clearly the distinction between the anapophysis and metapophysis, and of both from the 

 more constant processes of the vertebrae. To the left diapophysis of the first lumbar ver- 

 tebra a short pleurapophysis is anchylosed. Seven pairs of ribs directly articulate with the 

 sternum, which consists of six bones. A few of the haemal arches in the tail are preserved ; 

 their spines are long, compressed, and expanded. The transverse processes of most of the 



